Can I mix 8mm microbore central heating system with 22mm pipes?

[DrFrench]

Dear all,

Radiator related question - I'd like to know if I can mix a 8 mm microbore central heating system with 22 mm pipes? Specifically, a small section of pipe will be 22mm.
This will be an incremental upgrade – I appreciate the pump will have to work harder to pump water around the smaller pipes, but will 22mm pipes upset the system or should it all be 8 mm microbore?

Thanks for suggestions and help

 

[ecowarm]

Welcome to forum Dr, microbore systems normally have 22mm from the boiler to manifolds and from there 8mm (or 10mm) if its part of the 8mm you are altering I would stay with 8mm

 

[DrFrench]

Hi ecowarm,

Thank you for your response – we're planning to replace the 8mm microbore with 15mm (or 22mm), starting from the 22mm from the boiler ~ my concern is that this will starve the remaining, parallel 8mm circuits? My instinct says it won't make a difference, should be fine(?)

Thanks again

 

[ecowarm]

I know of quite a few mixed systems and all run on standard pumps

 

[SimonJohns]

Just need to be balanced afterwards.

Don't panic thou

Very simple and It's been done before

 

[AWheating]

like simon has stated, balancing the system correctly will be whats needed.

 

[DrFrench]

Many thanks for your prompt reply! I will go ahead with a mixed solution. I have another premises (Scottish Highlands) where I want to do GSHP (possibly bore hole rather than surface collector) with underfloor heating. It gets SO cold up there that a serious heating solution is required. The property has a small hydro-generator ~ 15kW - installed ~ 1900 which ran until the 1970's, so recommissioning this is my attempt to get this heating for free. Have you any expertise in this area? Or would you like the work?

 

[DrFrench]

>> Just need to be balanced afterwards.

How is this done?

 

[AWheating]

may be an idea to start another thread in the correct forum. Not that you wont get a reply, it also helps others who are looking for simular information search and find it better.

 

[ecowarm]

Many thanks for your prompt reply! I will go ahead with a mixed solution. I have another premises (Scottish Highlands) where I want to do GSHP (possibly bore hole rather than surface collector) with underfloor heating. It gets SO cold up there that a serious heating solution is required. The property has a small hydro-generator ~ 15kW - installed ~ 1900 which ran until the 1970's, so recommissioning this is my attempt to get this heating for free. Have you any expertise in this area? Or would you like the work?

I will PM you in the morning regarding GSHP Dr